In what was a historic year of progress for the equal rights of LGBT Americans, corporate America stood out as a true leader in the fight for basic fairness and dignity. Both inside the boardroom and in the halls of state legislatures and the U.S. Congress, American companies stood by their LGBT employees.

“This will go down in history as the year that corporate support for equality left the boardroom and reached each and every corner of this country,” said HRC President Chad Griffin. “Not only do fair-minded companies guarantee fair treatment to millions of LGBT employees in all 50 states, but now those same companies are fighting for full legal equality in state legislatures, in the halls of Congress and before the U.S. Supreme Court.”

In 2013, hundreds of major businesses signed onto historic amicus briefs urging the Supreme Court to strike down the discriminatory Defense of Marriage Act and California’s Proposition 8. Over 120 businesses joined a public coalition to urge Congress to pass the Employment Non-Discrimination Act, a proposed federal law that would provide consistent nationwide legal protections from workplace discrimination on the basis of sexual orientation and gender identity.

In addition to corporate America’s visible presence supporting LGBT rights publicly, the CEI reveals record numbers of major businesses updating their non-discrimination policies and benefits packages well ahead of federal mandates to support LGBT employees and their families.

The extent to which corporate America has adopted a full framework of LGBT inclusion was further evidenced by the rapid rise in workplace protections, health care benefits and practices for transgender employees. In just four years, the number of major employers covering medically necessary sex reassignment surgery for employees has gone from 49 to 340, including 28 percent of the Fortune 500. In addition, over 260 major employers have implemented more robust and supportive inclusion guidelines for their transitioning employees.

This rising tide of LGBT corporate engagement has picked up previously unlikely boats in the form of dozens of businesses across the South and Midwest taking initial steps, such as offering partner benefits and workplace non-discrimination protections, to attract and retain LGBT workers. This year’s CEI includes over 45 new major businesses. By proactively being a part of the CEI, these businesses sought to improve their reputations as employers of choice for LGBT and fair-minded workers.

The policies, benefits and practices businesses must implement to earn a perfect score are best-in-class demonstrations of corporate commitments to LGBT workers. In the inaugural CEI 12 years ago, 13 businesses earned a 100 percent. After two revisions to the scorecard in the following decade, major businesses kept apace and competed with one another, leading to the 304 top performers today. The top rated businesses span across industries, geographies and size.

“Corporate America has long recognized the imperative of LGBT inclusion by implementing their own LGBT-friendly policies ahead of lawmakers,” said Workplace Equality Program Director Deena Fidas. “We are at the front of a new era in which major businesses are not only meeting ever-higher new bars for workplace fairness, they are exceeding them by becoming social and public policy change agents in the process. They recognize equality is not just the right thing to do, it is sound business practice.”

Even with the tremendous progress, too many of America’s top companies, particularly from the oil & gas, mining, and manufacturing industries, are conspicuously absent from this movement toward equality. HRC will continue its outreach to the nation’s top employers and demand transparency from these companies in how they treat LGBT workers.

This year’s report at a glance:

In just two years under the most rigorous CEI criteria, the number of top-rated businesses has leapt from 189 to 304.

A record 300 major businesses and law firms publicly supported pro-equality legislation at the state and federal levels – including those that took an active role in the marriage equality campaigns.

This year’s CEI includes an all-time high of Fortune 500 companies with non-discrimination policies that cover gender identity (61 percent), while 86 percent of overall CEI participants cover gender identity.

Transgender-inclusive healthcare coverage continues to rise and is becoming a bellwether for full inclusion. Now in its third year as a mandatory criterion for a company to earn 100 percent, 340 (46 percent) participating companies offer comprehensive health care coverage to their transgender employees, up from 287 last year.

Beyond basic protections for LGBT employees, record numbers of American businesses have also updated their larger benefits packages, equalizing “soft benefits” for LGBT workers, including things like retirement benefits and relocation assistance. With benefits accounting for roughly 20 percent of an employee’s compensation, companies recognize this as a matter of equal pay for equal work.

Over the past 12 years, the CEI has become the gold standard for corporate policies and practices related to LGBT employees and their families. The CEI rates companies on 40 such policies and practices. A total of 931 businesses have been rated in the 2014 CEI, including the entire Fortune 500. This year, a record 299 of the Fortune 500-ranked businesses have official CEI ratings, with the other 197 unofficially rated based upon publicly-available data.